1. Field of the Invention
The present invention relates to an electrically powered motor.
2. Description of the Related Art
In the past, as a motor of a disk drive apparatus, there has been a motor including a bearing mechanism using fluid dynamic pressure. A conventional spindle motor disclosed in Japanese Patent Application Publication No. 2009-136143 includes a shaft, a first bearing component, a second bearing component, and a rotor component. The first bearing component is formed in a cup shape and a lower portion of the shaft is attached in a central opening of the first bearing component. The second bearing component is of an annular shape and is formed integrally with the shaft at an upper end portion of the shaft. The rotor component is disposed in an intermediate space defined by the shaft, the first bearing component, and the second bearing component. A fluid dynamic pressure radial bearing portion is formed between a cylindrical surface of the rotor component and an outer circumferential surface of the shaft.
A fluid dynamic pressure thrust bearing portion is formed between a lower surface of the rotor component and a surface of the first bearing component which axially faces the lower surface. A seal gap extending upward is defined in an outer side of the fluid dynamic pressure thrust bearing portion. A pumping seal portion is formed between a lower surface of the second bearing component and a surface of the rotor component which axially faces the lower surface. Another seal gap extending upward is defined in an outer side of the pumping seal portion.
Incidentally, in the conventional spindle motor shown in Japanese Patent Application Publication No. 2009-136143, since an upper seal gap extends farther upward than a radial gap, an entirety of the motor becomes taller by an amount corresponding to an axial length of the seal gap.